A proposed power output apparatus has an engine, a planetary gear unit that includes a carrier linked with a crankshaft of the engine and a ring gear linked with a drive shaft mechanically connected to an axle, a first motor that inputs and outputs power from and to a sun gear of the planetary gear unit, a second motor that inputs and outputs power from and to the drive shaft, and a battery that supplies and receives electric power to and from the first motor and the second motor (see, for example, Japanese Patent Laid-Open Gazette No. 11-187577). This power output apparatus sets an input restriction and an output restriction of the battery based on the temperature and the state of charge of the battery, and drives and controls the first motor and the second motor in the range of the settings of input restriction and output restriction.